function getTime() {
    var endTime = new Date('2022/5/11 00:00:00');
    var nowTime = new Date();
    var t = endTime.getTime() - nowTime.getTime();
    var d = 0;
    var h = 0;
    var m = 0;
    var s = 0;
    if(t>0) {
        d = Math.floor(t / 1000 / 60 / 60 / 24);
        h = Math.floor(t / 1000 / 60 / 60 % 24);
        m = Math.floor(t / 1000 / 60 % 60);
        s = Math.floor(t / 1000 % 60);
    }
    
    document.getElementById('daystime').innerHTML = d;
    document.getElementById('hourtime').innerHTML = h;
    document.getElementById('minutetime').innerHTML = m;
    document.getElementById('secondtime').innerHTML = s;
}

setInterval(getTime,0);

function Draw() {
    var number = document.getElementsByTagName('input');
    var luck = Math.floor(Math.random() * 100000000+1);
    number[0].placeholder = "恭喜您，您的抽奖号码是" + luck;
}
document.getElementById('btn').addEventListener('click',
    function (even) {
        Draw();
    },{once:true });